SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42105d2d541ee7cb3a30fcfcded5cb78d05d9fdcea16c85d534020b18950da58' 
  AND token = 'xBDuhPtY7VsSpXczECq5JN1gcgS0RcFVzvLKY5PUT30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables